The layers of the earth according to their physical properties:

1. Lithosphere  2. Asthenosphere 3. Mantle 4. Outer Core  5. Inner Core

The balance between temperature and pressure determines whether matter in earth's interior is solid, liquid, or somewhere in-between. In much of the earth's interior the high pressure will not allow the matter to melt even though the temperatures are very high.

The lithosphere includes the crust and the uppermost part of the mantle.    The cool, solid lithosphere floats on top of the asthenosphere.

The Asthenosphere
Scientists believe that below the lithosphere is a relatively narrow, mobile zone in the mantle called the asthenosphere (from asthenes, Greek for weak). This zone is composed of hot, semi-solid material, which can soften and flow after being subjected to high temperature and pressure over geologic time. The rigid lithosphere is thought to "float" or move about on the slowly flowing asthenosphere.

The Mantle
This layer is solid and rigid compared to the asthenosphere because the temperature is not high enough to overcome the high pressure.

The Outer Core
The outer core is liquid.  The circulation of its molten iron is thought to be the source of earth's magnetic field.

The Inner Core
There is very high pressure in the inner core.  As a result, even though the temperature is extremely high, the inner core is solid.
 

Answer the following questions.  Everyone in your group should hand
in their own answers - in complete sentences which restate the question.

1.  Based on their characteristic physical properties, what are the five
     zones (layers) of the earth?

2.  What does the lithosphere include?

3.  What is the hot, soft, and flowing condition of the asthenosphere called?

4.  What is the physical condition of the outer core?

5.  Why?

6. What is the physical condition of the inner core?

7. Why?

8. Consider the balance between temperature and pressure within the earth.
    How does depth affect temperature and pressure?